The present invention relates generally to fasteners for fastening two surfaces theretogether, and, more particularly, to a fastener for fastening a housing assembly theretogether.
Many electronic devices are comprised of electronic circuitry disposed upon one or more electrical circuit boards which are housed within a housing assembly. The housing assembly provides a supportive enclosure for supporting the electrical circuit boards therewithin and facilitates handling, and usage of the electronic device by a user.
Typically, the housing assembly is comprised of two portions. A first portion of the housing assembly is commonly referred to as a front (or top) housing assembly portion. And, a second portion of the housing assembly is commonly referred to as a rear (or bottom) housing assembly portion. The one or more circuit boards upon which the electronic circuitry of the electronic device is disposed is suitably positioned, or otherwise affixed, to one of the housing assembly portions. Thereafter, the other of the housing assembly portions is positioned in tandem with the first of the housing assembly portions so as to enclose the one or more circuit boards within the housing assembly in supportive enclosure therein.
Once the two housing assembly portions have been tandemly-positioned to enclose the one or more circuit boards in supportive enclosure therewithin, the housing assembly portions are typically fastened theretogether to maintain the housing assembly portions in tandem to maintain the one or more electrical circuit boards in the supportive enclosure.
Most simply, the housing assembly portions may be fastened theretogether by threaded shaft members engaging with the opposing housing assembly portions. Fasteners may also be integrally formed within the housing assembly portions such that, once the housing assembly portions are properly aligned to be tandemly-positioned, the housing assembly portions become fastened to one another by their mere proximity to one another.
Usually, when the fastener is integrally formed within the housing assembly portions, the fastener is formed of mated portions formed upon each of the housing assembly portions. Once the housing assembly portions are suitably aligned with one another to be tandemly-positioned thereby, mated engagement between the portions of the fastener result in the fastening of the housing assembly portions theretogether.
Use of such fasteners which are integrally formed with the housing assembly portions is particularly advantageous when the housing assembly portions are formed of a thermoplastic material as the fastener may be formed along with the housing assembly portions during molding of the housing assembly portions.
In some existing designs of fasteners comprised of the thermoplastic material and formed integral with the housing assembly portions, the fastener is constructed such that one portion thereof is flexible. When the housing assembly portions are positioned theretogether, the flexible, fastener portion of the fastener bends, or elastically deforms. Such fasteners are constructed such that the bending or elastic deformation of the fastener portion permits positioning of the fastener portions at a fastening position, thereby to fasten the housing assembly portions theretogether.
A flexing-member, snap-hook fastener is an example of such a fastener. In such a fastener, a rigid hook member is formed to protrude beyond a surface of one of the housing assembly portions. A flexible hook-retaining ring is formed upon the other of the other of the housing assembly portions. When the housing assembly portions are aligned with one another, the hook member protruding beyond a surface of one of the housing assembly portions engages with the flexible, hook-retaining ring.
Over time, the ability of such a flexing-member, snap-hook fastener to fasten adequately the housing assembly portions theretogether may be reduced due to loss of structural integrity of the flexible, hook-retaining ring of such a fastener. Loss of structural integrity of the flexible, hook-retaining ring may also occur after repeated use of such a fastener to fasten, and then to release, repeatedly, the housing assembly portions from their fastening engagement. Additionally, constructions of such a fastener requires specially-designed tools to release the fastener portions of the fastener from their fastening engagement to permit thereafter removal of the housing assembly portions from their tandem positions.
A radio transceiver, such as a radio telephone utilized in a cellular, communication system, is an example of an electronic device which typically is formed of one or more circuit boards supportively enclosed within a housing assembly. Radio telephone constructions operative in such a cellular, communication system are of many varied designs. One such design of a radio telephone is a mobile radio telephone which is constructed to permit mounting of the telephone within a vehicle. Another design of a radio telephone is a portable radio telephone.
Mobile radio telephones, constructed to be mounted permanently, or semi-permanently, in a vehicle need not be constructed to minimize the physical dimensions and weight thereof. Conversely, portable radio telephones, constructed to be carried by a user, are constructed to be of minimal physical dimensions and weight. In either type of radio telephone design, however, the radio telephone includes electronic circuitry disposed upon electrical circuit boards which are housed within a housing assembly, in manners described hereinabove.
Mobile radio telephones and portable radio telephones each include a handset having a speaker and a microphone supported therein. The handset typically further includes electrical circuitry disposed upon one or more circuit boards which, together with the speaker and the microphone, are housed within a housing assembly, similar to a housing assembly, as above-described.
In a portable radio telephone, the entire circuitry of the radio telephone is housed within the housing assembly of the handset. In a mobile radio telephone, typically, a portion of the circuitry of the radio telephone is housed within the housing assembly of the handset, and the handset is coupled to additional transceiver circuitry by way of a cable.
As the circuitry housed within the housing assembly of the radio telephone of either type of construction includes circuitry which generates high frequency signals as a byproduct of normal operation thereof (such signals are in addition to, and distinct from, the desired radio frequency signal transmitted upon a desired radio frequency channel by the radio telephone), the housing assembly must further function as a shield to prevent emanation of such high frequency signals. Accordingly, the housing assembly portions of the housing assembly, when fastened theretogether by one or more fasteners, must seat against one another in a manner to prevent emanation of the high frequency signals thereaway. Fastening of the housing assembly portions theretogether by the fasteners in such a manner is also advantageous for acoustic and aesthetic reasons.
Commercial assembly of such handsets is typically carried out in an assembly line-like manner. Fasteners utilized to fasten the front and rear housing assembly portions of the handset housing assemblies of such handsets of either design of radio telephone must permit quick assembly and fastening of the housing assembly portions theretogether by assembly line personnel.
Such design of fastener should permit the fastening theretogether of the housing assembly portions while not requiring manufacture of the handset housing portions to be within stringent manufacturing tolerances. Such design of fastener should also not be susceptible to loss of structural integrity.
What is needed, therefore, is a fastener for fastening portions of a housing assembly theretogether which does not require great precision of the fastener components and which is not susceptible to loss of structural integrity.